Villagers in large parts of north-east India were left reeling again last night after floods caused by three days of torrential rain engulfed entire communities, leaving around 50 people dead and 500,000 homeless.

Much of West Bengal, which was still clearing up after severe floods in August, remained underwater as the army and relief agencies tried to rescue survivors and take aid to homeless families.

Several districts remained cut off. Army helicopters and boats bringing supplies were yesterday unable to reach the worst affected areas, Murshidabad and Birbhum, because of rain and huge waves. Most of those who died were killed when their mud houses collapsed, while others were the victims of snakebites or drowned when their boats capsized.

"It has been raining for the past three or four days. There is water coming into our villages. The paddy fields are completely submerged. Now even snakes are entering our houses and several homes have collapsed," one villager told India's Star TV.

The latest floods come less than a month after unusually heavy monsoon rains brought destruction to south and north-east India, and to Bhutan, Nepal and Bangladesh. More than 400 people have died so far.

Some 10m people have been marooned by the latest rains, with road and rail links severely disrupted. Telecom workers protest ing against imminent privatisation had already paralysed phone lines in West Bengal. Last night the state's deputy chief minister, Buddhadev Bhattacharya, asked them to go back to work, saying their action made the relief effort more difficult.

The Indian Red Cross yesterday began distributing rice, pans, cooking oil, tarpaulins and mosquito nets. The International Red Cross has launched a $3.5m appeal, warning that with crops destroyed many villagers face severe debt.

"People are taking shelter wherever they can find it, in areas of high ground and in school buildings," N L Sharma, the Indian Red Cross's deputy director, said.